code: def test_real(self):
      for _ in range(self.test_epoch):
          # tensor
          x0, x1, x2, x3 = [self._rand_gen() for _ in range(4)]
          # function
          f_str = (
              "x0 + be.absolute(x1 + x2) + x3"
              "- (x0 + be.square(x1 + x2) + x3)"
              "+ (x0 + be.sig(x1 + x2) + x3)"
              "- (x0 + be.sig2(x1 + x2) + x3)"
              "+ (x0 + be.tanh(x1 + x2) + x3)"
              "- (x0 + be.tanh2(x1 + x2) + x3)"
              "+ (x0 + be.maximum(x0 + x1, x2 + x3) + x3)"
          )
          # gradient
          self._assert_grad_equal(f_str, [x0, x1, x2, x3], rtol=1e-2)
  
imports: from builtins import zip
  import numpy
  import pprint
  import pytest
  from neon import NervanaObject
  from neon.backends.autodiff import Autodiff
  from utils import allclose_with_out
label_desc: Use image node_id 11 for calling the TestAutodiff obj's underlying member method code with example usage: obj.test_real() without return types